Method and apparatus for functional imaging

Abstract

In a method and apparatus for functional imaging an impulse sequence is used in which an examination subject is charged with a readout gradient with sub-pulses of alternating polarity. By means of at least two-dimensional Fourier transformation, an image data matrix having N rows is generated from the raw data thereby acquired. After a stimulation of the subject, a second image data matrix is acquired. The coincidence of opposed signal changes that occur at two pixels disposed from each other by a distance of N/2 rows in the image matrix is checked. Found coincidences are evaluated as functional activity.

I claim as my invention: 
     
       1. A method for functional imaging of an examination subject by magnetic resonance, comprising the steps of: generating a basic magnetic field in which an examination subject is disposed;   stimulating said examination subject to produce neural activity in said examination subject;   conducting a measurement scan of said subject in said basic magnetic field after stimulation of said subject including charging at least a region of said subject with RF pulses, generating a phase-encoding gradient and reading out nuclear magnetic resonance signals arising in said examination subject under a readout gradient having successive pulses of alternating polarity to obtain scan values for each pulse;   entering the respective scan values for each pulse respectively in rows of a raw data matrix with directions of entry into said raw data matrix controlled dependent on the polarity of the respective pulse associated with the scan values, said raw data matrix having N rows;   generating an image data matrix having N rows from said raw data matrix by at least two-dimensional Fourier transformation, said image data matrix containing a plurality of pixels;   checking two pixels in said image data matrix disposed at a distance N/2 rows from each other for coincidence of opposed signal changes; and   evaluating coincidences of signal changes which are found as representing functional activity.   
     
     
       2. A method as claimed in claim 1 wherein said image data matrix includes a subject image having a central region and a ghost image, and wherein the step of evaluating said coincidences comprises identifying a coincidence as representing functional activity only for respective pixels in said central region and in said ghost image wherein a signal increase in said central region coincides with a signal attenuation in said ghost image displaced by N/2 rows. 
     
     
       3. An apparatus for functional imaging of an examination subject by magnetic resonance, comprising: means for generating a basic magnetic field in which an examination subject is disposed;   means for stimulating said examination subject to produce neural activity in said examination subject;   means for conducting a measurement scan of said subject in said basic magnetic field after stimulation of said subject including means for charging at least a region of said subject with RF pulses, means for generating a phase-encoding gradient and for reading out nuclear magnetic resonance signals arising in said examination subject under a readout gradient having successive pulses of alternating polarity to obtain scan values for each pulse;   means for entering the respective scan values for each pulse respectively in rows of a raw data matrix with directions of entry into said raw data matrix controlled dependent on the polarity of the respective pulse associated with the scan values, said raw data matrix having N rows;   means for generating an image data matrix having N rows from said raw data matrix by at least two-dimensional Fourier transformation, said image data matrix containing a plurality of pixels;   means for checking two pixels in said image data matrix disposed at a distance N/2 rows from each other for coincidence of opposed signal changes; and   means for evaluating signal changes which are found as representing functional activity.   
     
     
       4. An apparatus as claimed in claim 3 wherein said image data matrix includes a subject image having a central region and a ghost image, and wherein said means for evaluating said coincidences includes means for identifying a coincidence as representing functional activity only for respective pixels in said central region and in said ghost image wherein a signal increase in said central region coincides with a signal attenuation in said ghost image displaced by N/2 rows.